From patchwork Thu Sep 17 12:25:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roja Rani Yarubandi X-Patchwork-Id: 11782427 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 26B72746 for ; Thu, 17 Sep 2020 13:05:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 164BC21582 for ; Thu, 17 Sep 2020 13:05:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbgIQNEs (ORCPT ); Thu, 17 Sep 2020 09:04:48 -0400 Received: from alexa-out.qualcomm.com ([129.46.98.28]:29274 "EHLO alexa-out.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726785AbgIQMhH (ORCPT ); Thu, 17 Sep 2020 08:37:07 -0400 X-Greylist: delayed 485 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Sep 2020 08:36:02 EDT Received: from ironmsg09-lv.qualcomm.com ([10.47.202.153]) by alexa-out.qualcomm.com with ESMTP; 17 Sep 2020 05:27:51 -0700 Received: from ironmsg01-blr.qualcomm.com ([10.86.208.130]) by ironmsg09-lv.qualcomm.com with ESMTP/TLS/AES256-SHA; 17 Sep 2020 05:27:49 -0700 Received: from c-rojay-linux.qualcomm.com ([10.206.21.80]) by ironmsg01-blr.qualcomm.com with ESMTP; 17 Sep 2020 17:57:10 +0530 Received: by c-rojay-linux.qualcomm.com (Postfix, from userid 88981) id 072351AEA; Thu, 17 Sep 2020 17:57:08 +0530 (IST) From: Roja Rani Yarubandi To: wsa@kernel.org Cc: swboyd@chromium.org, dianders@chromium.org, saiprakash.ranjan@codeaurora.org, gregkh@linuxfoundation.org, mka@chromium.org, akashast@codeaurora.org, msavaliy@qti.qualcomm.com, skakit@codeaurora.org, vkaur@codeaurora.org, pyarlaga@codeaurora.org, rnayak@codeaurora.org, agross@kernel.org, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, sumit.semwal@linaro.org, linux-media@vger.kernel.org, Roja Rani Yarubandi Subject: [PATCH V4] i2c: i2c-qcom-geni: Add shutdown callback for i2c Date: Thu, 17 Sep 2020 17:55:58 +0530 Message-Id: <20200917122558.23110-1-rojay@codeaurora.org> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org If the hardware is still accessing memory after SMMU translation is disabled (as part of smmu shutdown callback), then the IOVAs (I/O virtual address) which it was using will go on the bus as the physical addresses which will result in unknown crashes like NoC/interconnect errors. So, implement shutdown callback to i2c driver to stop on-going transfer and unmap DMA mappings during system "reboot" or "shutdown". Store DMA mapping data in geni_i2c_dev struct to enhance DMA mapping data scope. For example during shutdown callback to unmap DMA mapping, this stored DMA mapping data can be used to call geni_se_tx_dma_unprep, geni_se_rx_dma_unprep and i2c_put_dma_safe_msg_buf functions. Add two helper functions geni_i2c_rx_msg_cleanup and geni_i2c_tx_msg_cleanup to unwrap the things after rx/tx FIFO/DMA transfers, so that the same can be used in geni_i2c_stop_xfer() function during shutdown callback. Remove "iova" check from geni_se_tx_dma_unprep and geni_se_rx_dma_unprep fucntions as invalidating with dma_mapping_error() is enough. Fixes: 37692de5d523 ("i2c: i2c-qcom-geni: Add bus driver for the Qualcomm GENI I2C controller") Signed-off-by: Roja Rani Yarubandi --- Changes in V2: - As per Stephen's comments added seperate function for stop transfer, fixed minor nitpicks. - As per Stephen's comments, changed commit text. Changes in V3: - As per Stephen's comments, squashed patch 1 into patch 2, added Fixes tag. - As per Akash's comments, included FIFO case in stop_xfer, fixed minor nitpicks. Changes in V4: - As per Stephen's comments cleaned up geni_i2c_stop_xfer function, added dma_buf in geni_i2c_dev struct to call i2c_put_dma_safe_msg_buf() from other functions, removed "iova" check in geni_se_rx_dma_unprep() and geni_se_tx_dma_unprep() functions. - Added two helper functions geni_i2c_rx_msg_cleanup() and geni_i2c_tx_msg_cleanup() to unwrap the things after rx/tx FIFO/DMA transfers, so that the same can be used in geni_i2c_stop_xfer() function during shutdown callback. Updated commit text accordingly. - In stop_xfer check whether it is tx/rx transfer using I2C_M_RD which is valid for both FIFO and DMA cases, so dropped DMA_RX_ACTIVE and DMA_TX_ACTIVE bit check of SE_DMA_DEBUG_REG0 register. drivers/i2c/busses/i2c-qcom-geni.c | 93 ++++++++++++++++++++++++------ drivers/soc/qcom/qcom-geni-se.c | 4 +- 2 files changed, 78 insertions(+), 19 deletions(-) diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index dead5db3315a..b0d8043c8cb2 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -86,6 +86,10 @@ struct geni_i2c_dev { u32 clk_freq_out; const struct geni_i2c_clk_fld *clk_fld; int suspended; + void *dma_buf; + size_t xfer_len; + dma_addr_t tx_dma; + dma_addr_t rx_dma; }; struct geni_i2c_err_log { @@ -307,7 +311,6 @@ static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c) spin_lock_irqsave(&gi2c->lock, flags); geni_i2c_err(gi2c, GENI_TIMEOUT); - gi2c->cur = NULL; geni_se_abort_m_cmd(&gi2c->se); spin_unlock_irqrestore(&gi2c->lock, flags); do { @@ -349,10 +352,62 @@ static void geni_i2c_tx_fsm_rst(struct geni_i2c_dev *gi2c) dev_err(gi2c->se.dev, "Timeout resetting TX_FSM\n"); } +static void geni_i2c_rx_msg_cleanup(struct geni_i2c_dev *gi2c) +{ + struct geni_se *se = &gi2c->se; + + gi2c->cur_rd = 0; + if (gi2c->dma_buf) { + if (gi2c->err) + geni_i2c_rx_fsm_rst(gi2c); + geni_se_rx_dma_unprep(se, gi2c->rx_dma, gi2c->xfer_len); + i2c_put_dma_safe_msg_buf(gi2c->dma_buf, gi2c->cur, !gi2c->err); + } +} + +static void geni_i2c_tx_msg_cleanup(struct geni_i2c_dev *gi2c) +{ + struct geni_se *se = &gi2c->se; + + gi2c->cur_wr = 0; + if (gi2c->dma_buf) { + if (gi2c->err) + geni_i2c_tx_fsm_rst(gi2c); + geni_se_tx_dma_unprep(se, gi2c->tx_dma, gi2c->xfer_len); + i2c_put_dma_safe_msg_buf(gi2c->dma_buf, gi2c->cur, !gi2c->err); + } +} + +static void geni_i2c_stop_xfer(struct geni_i2c_dev *gi2c) +{ + int ret; + u32 geni_status; + + /* Resume device, as runtime suspend can happen anytime during transfer */ + ret = pm_runtime_get_sync(gi2c->se.dev); + if (ret < 0) { + dev_err(gi2c->se.dev, "Failed to resume device: %d\n", ret); + return; + } + + geni_status = readl_relaxed(gi2c->se.base + SE_GENI_STATUS); + if (!(geni_status & M_GENI_CMD_ACTIVE)) + goto out; + + geni_i2c_abort_xfer(gi2c); + if (gi2c->cur->flags & I2C_M_RD) + geni_i2c_rx_msg_cleanup(gi2c); + else + geni_i2c_tx_msg_cleanup(gi2c); + gi2c->cur = NULL; +out: + pm_runtime_put_sync_suspend(gi2c->se.dev); +} + static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, u32 m_param) { - dma_addr_t rx_dma; + dma_addr_t rx_dma = 0; unsigned long time_left; void *dma_buf = NULL; struct geni_se *se = &gi2c->se; @@ -372,6 +427,10 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, geni_se_select_mode(se, GENI_SE_FIFO); i2c_put_dma_safe_msg_buf(dma_buf, msg, false); dma_buf = NULL; + } else { + gi2c->xfer_len = len; + gi2c->rx_dma = rx_dma; + gi2c->dma_buf = dma_buf; } geni_se_setup_m_cmd(se, I2C_READ, m_param); @@ -380,13 +439,7 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, if (!time_left) geni_i2c_abort_xfer(gi2c); - gi2c->cur_rd = 0; - if (dma_buf) { - if (gi2c->err) - geni_i2c_rx_fsm_rst(gi2c); - geni_se_rx_dma_unprep(se, rx_dma, len); - i2c_put_dma_safe_msg_buf(dma_buf, msg, !gi2c->err); - } + geni_i2c_rx_msg_cleanup(gi2c); return gi2c->err; } @@ -394,7 +447,7 @@ static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, u32 m_param) { - dma_addr_t tx_dma; + dma_addr_t tx_dma = 0; unsigned long time_left; void *dma_buf = NULL; struct geni_se *se = &gi2c->se; @@ -414,6 +467,10 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, geni_se_select_mode(se, GENI_SE_FIFO); i2c_put_dma_safe_msg_buf(dma_buf, msg, false); dma_buf = NULL; + } else { + gi2c->xfer_len = len; + gi2c->tx_dma = tx_dma; + gi2c->dma_buf = dma_buf; } geni_se_setup_m_cmd(se, I2C_WRITE, m_param); @@ -425,13 +482,7 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, if (!time_left) geni_i2c_abort_xfer(gi2c); - gi2c->cur_wr = 0; - if (dma_buf) { - if (gi2c->err) - geni_i2c_tx_fsm_rst(gi2c); - geni_se_tx_dma_unprep(se, tx_dma, len); - i2c_put_dma_safe_msg_buf(dma_buf, msg, !gi2c->err); - } + geni_i2c_tx_msg_cleanup(gi2c); return gi2c->err; } @@ -630,6 +681,13 @@ static int geni_i2c_remove(struct platform_device *pdev) return 0; } +static void geni_i2c_shutdown(struct platform_device *pdev) +{ + struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev); + + geni_i2c_stop_xfer(gi2c); +} + static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev) { int ret; @@ -694,6 +752,7 @@ MODULE_DEVICE_TABLE(of, geni_i2c_dt_match); static struct platform_driver geni_i2c_driver = { .probe = geni_i2c_probe, .remove = geni_i2c_remove, + .shutdown = geni_i2c_shutdown, .driver = { .name = "geni_i2c", .pm = &geni_i2c_pm_ops, diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c index d0e4f520cff8..0216b38c1e9a 100644 --- a/drivers/soc/qcom/qcom-geni-se.c +++ b/drivers/soc/qcom/qcom-geni-se.c @@ -705,7 +705,7 @@ void geni_se_tx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len) { struct geni_wrapper *wrapper = se->wrapper; - if (iova && !dma_mapping_error(wrapper->dev, iova)) + if (!dma_mapping_error(wrapper->dev, iova)) dma_unmap_single(wrapper->dev, iova, len, DMA_TO_DEVICE); } EXPORT_SYMBOL(geni_se_tx_dma_unprep); @@ -722,7 +722,7 @@ void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len) { struct geni_wrapper *wrapper = se->wrapper; - if (iova && !dma_mapping_error(wrapper->dev, iova)) + if (!dma_mapping_error(wrapper->dev, iova)) dma_unmap_single(wrapper->dev, iova, len, DMA_FROM_DEVICE); } EXPORT_SYMBOL(geni_se_rx_dma_unprep);